It's a Potter-Evans Thing
by Lilybelmae
Summary: After a potions accident, Lily Evans and James Potter end up swapping bodies with each other. Will James and Lily finally stop loathing each other and fall in love? Will Lily kill James? Will they ever switch back? Read and find out!
1. Chapter 1

**Hello everyone!**

 **So I know I haven't written in a while but here's a new story for you all!**

 **Also here's Lily and James with the disclaimer:**

 **Lily: Lilybelmae does not and never will own the Harry Potter franchise**

 **James: The honour of owning said franchise belongs to the lovely and talented Miss JK Rowling**

 **Lily: Don't interrupt me Potter!**

 **James: Hey! She said we could both do it!**

 **Lilybelmae: Ok you two, that's enough! (Lily and James glare at each other and at said author but nonetheless stop talking) Alright, on with the story!**

Lily Evans sighed as she marched into her Potions class. She sat down at an empty desk and waited for Professor Slughorn to arrive. Lily had arrived on time as usual because she was Head Girl and in her mind the Head Girl had to be on time in order to set an example for the other students at Hogwarts. The Head Boy, James Potter, was of course nowhere to be seen. No doubt he'd strut in at the last minute with that stupid smirk on his face and plunk down next to his best friend Sirius Black or his girlfriend Beatrice Talbot.

It's not fair, Lily thought grumpily, that James can just strut in late for class and have everyone still respect him just because he's pureblood while I have to work extra hard to get respect from anyone because I'm muggleborn. Lily also didn't like the fact that James had three friends in Potions with him while she only had her best friend Alice who was out sick with the flu.

Just then, James Potter in all his glory came strutting into the room. He didn't see the big deal about showing up at the last second. After all, as long as he showed up to class on time what was the difference? Unfortunately for both Lily and James, all the desks in the class were full including James' usual seat next to Sirius Black, which was occupied by their other friend Remus Lupin. The only empty seat in the classroom was the one next to Lily, which was usually occupied by Alice. What was the matter with them sitting next to each other you might ask? Well, Lily Evans had detested James Potter since she met him on the Hogwarts Express in their first year. James had also originally detested Lily and had pranked her and her then best friend Severus Snape all the time for a while. Then, James had stopped pranking Lily in fourth year and ever since then had developed a nasty little habit of asking Lily out on a date constantly.

He asked her out at breakfast, in classes, at lunch, at Quidditch practices, while he was bullying other students, at supper, before bed and just whenever he saw her really. And it drove Lily to the brink of insanity more times than she could count. After all, she'd never give a bullying git like Potter the time of day. And then all at once, James had started going out with a Ravenclaw called Beatrice Talbot at the end of sixth year and had stopped asking Lily out. This relieved Lily to no end but she still wasn't the biggest fan of James Potter. Regardless, James plunked down next to her anyway, much to Lily's annoyance.

"Alright, Evans?" James smirked.

"Fine, Potter," Lily said coldly. "And yourself?"

"Well I was fine until I got stuck sitting next to you," James sighed.

Lily growled and was about to retort when Professor Slughorn arrived.

"Good Morning, Class," the Professor greeted warmly.

"Good Morning, Professor Slughorn," the seventh years chorused back.

"Today we are brewing switching solutions," Slughorn explained. "You will be completing the assignment in pairs. Your partner is the person sitting next to you."

The class groaned.

"I want no complaints!" Slughorn called above the din of voices. "The assignment is due at the end of class."

"Great," James moaned.

"Just peachy," snapped Lily. "Alright, Potter, I want no funny business. This potion is extremely difficult to brew and if you make just one mistake we are both doomed. Do you understand?

"Yes, Miss Bossy Boots," James drawled. "Don't get your knickers in a knot"

"Don't be rude, Potter," Lily hissed. "Now get to work before I hex you!"

For the next few minutes, Lily and James worked in peace, ignoring Sirius' wide eyes at the pair being so quiet and Beatrice's growls at another woman being near her man. Then as the pair finished adding the last of the ingredients to the cauldron, James accidentally added too much knot grass causing the potion to explode all over himself and Lily. Lily gave James such a glare that if looks could kill, James would be a dead man.

" _Look what you did, you clumsy idiot!"_ Lily screeched at James. _"All of my hard work is ruined thanks to you!"_

" _Is school work all you care about, Evans?!"_ James roared back, _"God, you're such a stuck up little swot!"_

" _Well, better a swot than an arrogant, bullying, self-absorbed toerag like you!"_ Lily bellowed.

" _I am_ _ **not**_ _a bullying toerag Evans!"_ James screamed, _"How dare you call me that again!"_

" _Oh yes, you are!"_ Lily shot back. _"And another thing, Potter, you think you're the King of the World? Well guess what?! You'd_ _ **never**_ _last one day in my shoes!"_

" _Oh yes, I_ _ **would**_ _Evans!"_ James retorted angrily. _"All the professors love you, you get perfect grades and you have every guy in this bloody school getting a hard on for you! Your life is perfect compared to mine!"_

" _Are you_ _ **mental**_ _Potter?! You think my life is perfect?!"_ Lily yelled. _"You'd never last an_ _ **hour**_ _in my life!_ _ **I**_ _on the other hand could probably last longer in your easy, carefree life riding a bloody broomstick for hours, playing stupid, moronic pranks and snogging Talbot!"_

" _OI! My life is_ _ **not**_ _easy or carefree!"_ James angrily spat. _"It's harder than you think you_ _ **fucking**_ _priss!"  
_

" _I_ _ **hate**_ _you, you lazy, infuriating, arrogant little prat!"_ Lily shrieked.

" _And I_ _ **hate**_ _you, you stuck-up, know-it-all, bossy little swot!"_ James hollered back.

"I'LL _**NEVER**_ UNDERSTAND YOU!" They shouted together.

As Lily and James barked at each other they failed to notice that the potion that had exploded on them had seeped through their robes and into their skin. Later that night, as James and Lily slept, the potion began to work its magic...

 **Duh duh duh! Cliffhanger! Please read and review my lovelies!**


	2. Chapter 2

**Alright, sorry I took so long with the update! Here's the next installment of** _ **It's a Potter-Evans Thing.**_ **And now here's Lily and James with the disclaimer.**

 **James: Lilybelmae does not own the Harry Potter universe.**

 **Lily: The lovely and talented JK Rowling, however, does.**

When Lily woke up the next morning, she immediately realized that something was not right. For one thing she was in the boys dormitory, which smelled strongly of male body odor and flatulence. Lily could tell because Sirius was sleeping in a bed to one side of her and Remus was sleeping in a bed on the other side. For another, she couldn't see very well and the world had gone blurry.

"Aaargh! I've gone blind! Someone help!" Lily called in a deep voice that was certainly not her own.

"Prongs, you haven't gone blind you moron," Sirius laughed. "Your glasses are on your trunk you dolt"

Glasses? Thought Lily, since when have I ever worn glasses? And why the hell is Sirius calling me Prongs? Lily pushed those thoughts aside and crawled to the end of the bed, reaching for a pair of familiar looking spectacles on the trunk in front of it. She shoved the glasses on her face and walked into the boys' dormitory bathroom to use it. As she went to use the toilet she was pretty disturbed to find out her junk had changed into that of a boy's overnight. After that experience she barely had time to register her shock before looking in the mirror whilst washing her hands. The reflection in the mirror made Lily scream. Looking back at her was not her own reflection but that of a shirtless and underwear clad James Potter. Blushing, Lily shot of the boys' dormitory, past the bewildered looking Marauders towards the common room. She knew she and James would need to have a little chat.

Meanwhile, when James woke up he too immediately realized that things were not as they should be. Instead of waking up in the boys' dormitory, he was in the girls' dormitory, which smelled potently like a mixture of different fruity and flowery perfumes. He also wasn't sleeping between Sirius and Remus' beds anymore but rather those of Alice Fortescue and Mary MacDonald. And, oddly enough, he didn't need his glasses to see. As he went to use the bathroom he caught sight of junk and his eyes widened in shock. He no longer had boy parts but rather girl parts, which embarrassingly forced him to sit to pee. When James caught sight of his reflection in the girls' dormitory bathroom mirror, he shrieked in shock. Instead of his own handsome face looking back at him, he was looking into the face of Lily Evans. He dashed down the stairs passed the annoyed girls, knowing he'd need to find himself immediately.

It didn't take long for Lily and James to find each other as they ran straight into each other at the bottom of the stairs. Lily stood up, looked James straight in the eye and hissed,

"Myrtle's bathroom. _**Now**_."

"Of course," James agreed hastily, "Just don't forget to put on some robes. Handsome as I am, I don't want all of Hogwarts to see me in just my pants."

Lily looked down and blushed as she realized that James was right and that she wearing only a pair of light blue box shorts. She also caught sight of the fact that James was wearing only an extra large Weird Sisters t-shirt and spat,

"You too, Potter."

"Why, Evans?" James grinned cheekily. "I think I look rather sexy in this shirt."

"Well I don't want all of Hogwarts to see me half naked you perverted arse!" Lily shot back. "Now, get dressed and meet me in Myrtle's bathroom!"

"Ok, ok," James conceded. "Don't get your knickers or should I say boxers in a knot"

Lily glared at James before stomping back up to the boys' dormitory to get changed. She grabbed robes nearest to the bed she'd been sleeping in, threw them on and put on some shoes. Then, she stomped down to the common room and out of the portrait hole. She made it to Moaning Myrtle's bathroom before James but didn't have to wait long before James stumbled into the girls' loo. As soon as she saw him, Lily shouted,

" _What did you do to us, Potter?!"_

"Me?!" protested James. "What makes you think this has anything to do with me?!"

"Oh, I don't know," Lily spat out sarcastically. "Perhaps the fact that you exploded switching serum on us in potions class yesterday! I knew I shouldn't have let you put the knotgrass in!"

"It's not like I meant to put in that extra bit!" James argued. "It just slipped out of my hand!" 

"Slipped out?! Slipped out?!" Lily snipped. "That's the lamest excuse I've ever heard Potter!"

"Would you stop yelling at me, Evans!" James snapped back. "We need to figure out what to do and pointing fingers isn't going to help!"

"Ugh! Fine! But just so you know, Potter, it's _**YOUR**_ fault!" Lily bit back. "I think we need to tell our friends.

"What?!" James gasped in horror. "No way Evans! Absolutely no way!"

"Why the bloody hell not, Potter?!" Lily barked.

"Because, Evans, they'll think we're bloody mad!" James snarled. "Think about it! What would you say to Alice and Sirius for instance if they told you they'd switched bodies?"

"Well, I'd probably tell them they were mental unless they brought me some proof," Lily reluctantly admitted.

"See?" James sighed. "The only problem is how are we going to keep this a secret? I mean I think my mates would probably notice something's up and so would yours" 

"For once I think you're right," Lily agreed. "I think we'd better go to Slughorn and Dumbledore about this and figure out what to do."

"Alright, then," James drawled as he opened the bathroom door, "After you"

The two exited the bathroom with Myrtle roaring hysterically in laughter behind them.

 **Myrtle: Oh, this is dreadful! Hahahaha, oh you should have seen them! (Laughs hysterically)**

 **James and Lily: SHUT UP MYRTLE!**

 **Myrtle: Waaahhhhhhh! (Floats off)**

 **James: WHAT HAVE YOU DONE TO US, LILYBELMAE?!  
Lily: CHANGE US BACK NOW OR I'LL-**

 **Lilybelmae: (interrupts Lily and dodges hexes from both Heads): Now, please read and review!**


	3. Chapter 3

**I'm so sorry I haven't updated in awhile! I've been super busy with work lately and also other plot bunnies have been demanding I write about them. But enough excuses, I'd better hide as here comes Lily and James with the disclaimer.** _ **Lilybelmae runs away, dodging a hex from Lily and James.**_

 **Lily: That disgrace of an author, Lilybelmae, thankfully does not own the** _ **Harry Potter**_ **universe.**

 **James: The universe is owned by the supremely talented and beautiful JK Rowling.**

Lily and James hurried to the Headmaster's office as quickly as their legs would carry them. They did not want to be stuck in each other's body for any longer than was necessary. It was already pretty awkward just looking at each other never mind living as each other. When they reached Dumbledore's office, Lily called out,

"Cauldron cakes!"

The staircase to the office appeared and the Head Boy and Girl quickly climbed up, hoping the Headmaster was there to help them. They entered Dumbledore's office and saw the old wizard sitting cheerfully at his desk, filling out forms and eating yellow lemon shaped candies.

"Why, hello Mr. Potter," he said, looking at Lily's body. "And hello to you too, Miss Evans," looking this time at James' body. "What brings the two of you here this morning?"

"Well," James admitted rubbing the back of his, or rather Lily's, head. "Evans and I had a row yesterday during potions and I accidentally added the wrong amount of knot grass to the switching solution we were brewing and it exploded on us causing us to switch bodies,"

"I see," Dumbledore replied calmly. "I better call Professor Slughorn in immediately as I do not know for certain what the antidote is for switching solution. Please have a seat, he should be here shortly."

The two Heads sat together quietly for once and ashamed that their squabbling lead to this incident. It wasn't long before Professor Slughorn arrived and he looked far from happy.

"Lily and James, I am so disappointed in you," Slughorn scolded. "You know better than to walk away if a potion has spilt on you. You should've gone directly to the hospital wing,"

"Yes, Professor," Both Heads answered sheepishly.

"As it is," Slughorn went on. "Switching solution must be rubbed off as soon as it touches you to prevent something like this from happening. Since it's too late for that you must unfortunately wait for it to wear off,"

"But, Professor-" Lily began.

"I do not want to hear excuses, Lily," Slughorn cut her off. "I wish there was an antidote as much as you do, but unfortunately it takes about a month for this to wear off and the two of you will just have to put up with being each other until then,"

"Alright," Lily conceded.

"Should we tell anyone?" asked James.

"Absolutely not," Dumbledore answered firmly, giving James a pointed look. "We don't want any of the other students to use this unfortunate incident as inspiration for mischief. You'll just have to learn to be each other. You are dismissed,"

"Yes, Professor," the Heads replied in unison, then they headed back down to the Great Hall for breakfast.

When they arrived at the Great Hall, Lily had to fight her impulse to go sit next to Alice and Mary, whilst James had to fight his to go and sit with the Marauders. Lily sat down next to Sirius who chortled mirthfully,

"There you are! We were beginning to think you'd lost it this morning. Eat up!"

Lily stared down at a massive English fry-up and gulped. Now, being raised in Great Britain, you'd think Lily would love the combination of fried bread, fried eggs, bacon, sausage, baked beans, and black pudding. Lily, however, abhorred fry-ups as she thought they were greasy and disgusting. She couldn't refuse to eat the one in front of her however because it was James' favourite breakfast apparently and to do so would give away that there was something amiss with James. So, Lily picked up her fork and began to eat the beans first, which caused Remus to give her a weird look.

"What?" Lily asked, a forkful of beans dangling halfway to her mouth.

"Nothing, it's just I've never seen you eat your beans first," Remus replied. "Like ever. Usually, you scarf down your bacon first. You feeling alright, mate?"

"I'm fine, Remus," Lily insisted. "Never better,"

"You sure you're ok, Prongs?" Sirius asked reaching out to feel "James'" forehead.

"Yes, why?" Lily asked, slightly agitated.

"Because you never call us by our first names, Prongs," Sirius pointed out. "Only ever by our nicknames. Are you sure you didn't whack your head or something when your potion exploded yesterday?"

"Yes, Si-I mean Padfoot, I'm fine!" Lily grumbled. "Now bugger off and let me eat!"

"Alright, Mr. Grumpy, geez!" Sirius huffed putting his hands up in surrender.

Lily looked back to the fry-up and started gagging down the bacon. She shuddered and tried not to make a face at its greasiness. Down the table, James, who was sitting next to Alice, was faring no better with his breakfast of porridge. James loathed porridge; the texture grossed him out and he couldn't believe that Lily liked this stuff. He had a harder time keeping the disgusted look off his face, which caused Alice to cry out,

"Lily, are you feeling alright, love?"

"Er, yes, Alice, why?" James asked.

"Because you're making faces at your porridge and you look like your about to throw up." Alice pointed out. "You love porridge, are you sure you're feeling ok?"

"Yes, Alice," James groaned in annoyance. "I'm fine!"

"Ok," Alice surrendered. "Just don't come crying to me if you throw up later,"

The two Heads managed to make it through breakfast without further incident, but the day was only beginning. James had to fight to keep himself awake and take notes in Lily's arithmancy class, knowing she'd kill him if he made her look lazy. He also had to put up with people being down right horrendous to him in the halls. Ok, they were being jerks to Lily, but it was still hurtful and irritating. They gossiped about her, calling Lily a "goody-goody" and "Dumbledore's Number One Swot". It made James sick to hear these comments and it was taking every ounce of strength inside him not to hex all these people into oblivion. No wonder Lily complained about having to work hard to maintain her image as Head Girl, James thought. People were downright cruel and disrespected Lily left, right, and centre if she didn't keep up a perfect image. James was just about at his limit when he heard a Slytherin boy say,

"Out of my way you dirty, kiss-arse mudblood,"

James' blood boiled and he did something down right stupid: he hexed the boy with a stinging hex to his abdomen so strong it made the Slytherin wet himself. The whole hallway burst into hysterics, but this was short lived as Professor McGonagall made her way up behind "Lily".

"Miss Evans!" McGonagall gasped. "I never would have expected this from you! Five points from Gryffindor and you have detention with me tomorrow evening at 7:00 p.m. sharp!"

James gulped and nodded, not believing how fowl his luck had turned. He hurried outside to Quidditch practice, dreading facing Lily.

Lily, meanwhile, had to fight her urge to make meticulous notes in class and just make adequate ones with doodles scribbled on the edges. It didn't help her case that the Marauders, especially Remus, kept giving her weird looks all day as she had to be reminded of several inside jokes amongst the boys. Trying her best to keep in character, Lily hexed a random Slytherin kid in the hall. Remus pulled her aside and hissed,

"Prongs, what the bloody hell do you think you're doing?!"

"What are you talking about Re-Moony?" Lily asked confusedly.

"Why did you just hex that kid?" Remus asked exasperatedly. "He didn't do anything to us! I thought you stopped hexing random people for fun!"

"I did?" Lily asked. "I mean I did, you're right, Moony, it's just old habits die hard and-"

"Yeah, yeah, save it Prongs," Remus sighed. "You know since you did it in full view of Professor Flitwick, I have to give detention right?"

"Oh, shit!" Lily swore.

"What do you care?" Sirius asked. "It's not like you don't get detention all the time anyways,"

"I know, but I don't want to be a bad influence," Lily snapped.

"Don't get your knickers in a knot, Prongs," Sirius laughed, putting up his hands in mock surrender.

Lily glared at Sirius as Remus cut in,

"Your detention is tomorrow at 7 p.m., Prongs,"

"Alright," Lily moaned. "I'll be there. I better get to quidditch practice before the team gets ticked off at me for being late,"

Lily and James both arrived at quidditch practice at 6 p.m. sharp and were about to go to their usual changing rooms when they realized that they were not in their original bodies and would have to go to the opposite gender's changing room. After an awkward time changing in front of the opposite gender, Lily, James and the rest of the Gryffindor quidditch team headed out onto the pitch for practice. "James" decided that everyone would work on their specific skill, such as chasers passing and shooting, for the duration of practice. This allowed James to teach Lily how to be a chaser and Lily to teach James how to be a seeker. While James picked up seeking very easily, Lily was having some trouble learning to be a chaser.

"Come on, James!" "Lily" shouted. "You've got this! Just get those dust bunnies out of your head and keep your eye on the quaffle,"

"Ok," "James" sighed nervously as "he" held his hands out to catch the quaffle.

To Lily's surprise, she caught the quaffle perfectly and managed to throw it back to Sirius perfectly too. The rest of practice was uneventful, until Beatrice Talbot showed up at the end. Lily was putting away the equipment with Sirius and Marlene McKinnon's help when Beatrice walked up to "James" smiling.

"Good work today, Jamesie-poo," Beatrice cooed. "You were soooo wonderful! Gryffindor is sure to win the Quidditch cup thanks to my handsome wandsome, boyfriend!"

And with that, Beatrice launched herself at "James" and smooched him hard. Lily shoved Beatrice off of her, shocked.

"What the hell, James!" Beatrice shouted.

"Sorry, Tal-I mean Beatrice," Lily sighed. "I just wasn't expecting you to kiss me. Look, I'm not myself right now so I really don't think it's a good idea for us to be dating."

"Why not?" Beatrice pouted.

"Because, I'm just not fancying you at the moment ok?!" Lily yelled. "Your cooing is annoying and I'm hot and sweaty and need a shower and I don't need you launching yourself at me while I'm like this! Just back off Talbot!"

"How dare you yell at me!" Beatrice squawked indignantly. "You are such an arsehole, James Potter! We're through!"

Before Lily could get in another word, Beatrice slapped her across the face, hard. Lily fell back a few steps in pain and was rubbing her cheek when James reached up, grabbed her by the ear, and pulled her aside.

"What the hell is wrong with you?!" James hissed. "You made my girlfriend break up with me!"

"I'm sorry, Potter," Lily whimpered, cheek still in searing pain. "I just didn't think I should be dating your girlfriend while I'm in your body. I'm not a lesbian and I'm not you and it wouldn't be fair to Beatrice for someone who is impersonating her boyfriend to date her. I won't take advantage of her to preserve your relationship, Potter, I just won't,"

"Alright," James agreed. "Fair enough. I can win her back easily enough, I guess. Look, I have to admit something to you, Evans. I got you a detention, but I swear that Slytherin had a dirty mouth!"

"What?!" Lily roared. "Potter, I can't just be getting detentions! If my reputation is ruined, they'll get somebody else for Head Girl! I got you a detention I was going to apologize for but since you got me one, I guess we're even!"

"I guess so!" James snarled. "God, this couldn't be going worse!"

"I'll say!" another voice piped up.

James and Lily whirled around to see Remus, Sirius, Peter, Alice, and Marlene staring at them.

"Just who the hell are you two and what have you done to Lily Evans and James Potter?" Remus asked firmly and quietly.

 **Lilybelmae (peeking her head back in): Please review, review, review! (dodges hexes) Ahhhh! (runs off)**

 **Lily and James: GET BACK HERE AND CHANGE US BACK LILYBELMAE!**


End file.
